Pub brings in satellite after opening? It's born of necessity! (9)
I believe the answer is:
invention
'it's born of necessity' is the definition.
('necessity is the mother of invention')
'pub brings in satellite after opening?' is the wordplay.
I cannot really see how this works, but
'in' is found in the answer.
'satellite' could be 'io' (Io is a moon of Jupiter) and 'io' is present in the answer.
'opening?' could be 'vent' (vent is a kind of opening) and 'vent' is found within the answer.
A single letter 'n' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
(Other definitions for invention that I've seen before include "of necessity, a child?" , "Creation of something new" , "Creation of a device or new process" , "displaying creativity" , "untruth" .)